This invention relates to containers and, more particularly, to an injection molded plastic drum with a reinforced sidewall.
In one form of a conventional shipping and storage container, an enlarged drum is used. The drum may be, for example, a fifty five gallon drum. Such drums have found wide usage for shipping and storing liquid or granular products. For example, such drums have been used for storing food products and for storing hazardous products.
In its simplest form, a drum includes a single tubular sidewall closed at one end by a bottom wall. Such containers typically have either a fiberboard or metal sidewall of uniform thickness. More recently, plastic drums have found wide acceptance.
During shipping and storage, such plastic drums are often stacked to conserve space. When filled plastic drums are stacked, however, the additional weight bearing on a bottom drum in a stack may cause significant deformations of the bottom drum. In such a case, a lower portion of the bottom drum typically bulges outwards. resulting in an xe2x80x9celephant footxe2x80x9d shaped bottom drum. This deformation produces an internal pressure within the bottom drum, forcing the contents of the bottom drum to escape.
The present invention is intended to solve one or more problems discussed above in a novel and simple manner.
In accordance with the invention there is provided a unitary plastic drum.
Broadly, there is disclosed herein a plastic shipping container including a unitary plastic drum having a generally cylindrical sidewall closed at a bottom end with a bottom wall and open at an upper end. The drum is of one-piece plastic construction.
It is a feature of the invention that at a lower section of the sidewall is double-walled.
It is another feature of the invention that a center section of the drum includes a diameter that decreases from the drum top downwards.
It is another feature of the invention that an upper section of the drum have a greater diameter than a diameter of the center section, thereby creating a conical ledge on the inner surface of the drum.
It is another feature of the invention that the lower section has a smaller diameter than the center section diameter such that a ledge is formed to aid in the nesting of empty drums.
It is yet another feature of the invention to include a second cylindrical sidewall concentric to and extending at least partially the length of the first sidewall.